Tammy Jamieson

Tammy Jamieson
Major: pre-Medical Laboratory Sciences, College of Health Sciences
Class rank/time of internship: Sophomore, Summer 2014
Mentors: Ricky Lewis, Jason Unrine, and Dave McNear
Collaborations:Environmental Chemistry and Toxicology & Rhizosphere Laboratories, Plant and Soil Science Dept (CAFE)

Title:Examining the Impact of Manufactured Nanomaterial Surface Charge on Respiration, Viability, and Macrocolony Formation of Bacillus subtilis

Project Desription: The objective of this work was to determine the role of nanoparticle surface charge in toxicity of Bacillus subtilis. We used ceria nanoparticles that were covered in particular coatings to impart various charges in order to study the surface chemistry of toxicity on the bacteria. The coatings used on the ceria nanoparticles were dextran for a neutral charge, carboxymethyl-dextran (CM-D) for a negative charge & diethylaminoethyl-dextran (DEAE-D) for a positive charge. We used viability & respiration assays as well as assessing macrocolony formation after exposures.

Conclusions from her research (link to results):

  • The positively charged, DEAE-Dextran coated CeO2 nanoparticles were the most toxic particles we tested
  • The viability assay revealed dose dependent responses,
  • The respiration assay and RSI metric revealed dose dependent metabolic responses to the positively charged Ce nanoparticles, some of which were sublethal.
  • Particle coating had little influence on bacterial viability or physiology
  • While we developed a new, high throughput method for assessing macrocolony formation, we found little influence on this behavior.

On her internship experience:

How has the internship influenced you?

This internship was not in my area of study. My area of study is medical laboratory science (I am in the MLS program at UK) but the internship was a collaborative effort between the Environmental Chemistry and Toxicology Laboratory (we sometimes call this the Nano lab for short, as they work with nanoparticles) & the Rhizosphere Science Laboratory at the University of Kentucky. This was great because I was able to gain a new perspective - a new lens through which I could view an inquiry, as well as new (new to me) methods that could be employed & new ways to navigate practicing science. Getting to combine what I had learned in my field of study with what my mentor was teaching me in a different branch of science was a great experience. I have noticed that the people in different branches of science tend to flock together. I don’t think this is a bad thing; after all, we should support each other in our endeavors, but I would like to see more merging of minds from different branches of science on a more regular basis. I support this approach now more than ever after having experienced it for myself. Being an expert in one area is great of course, but that doesn’t mean areas outside of your expertise don’t have something to offer, like new ways of thinking about &/or approaching problems and questions.

If you reflect over what you knew when you started and what you hoped to gain from the experience, did it affirm your plans for continued study/research/major in the area or redirect you? 

This experience definitely helped to confirm my decision to pursue the sciences. I gained valuable practical skills & insight while strengthening my problem solving skills & widening my perspective. Although it did not redirect me, it did inspire & teach me. I also made some new friends within the labs I worked in & formed new connections within the labs that I did not have before. I gained everything I had hoped for through this internship experience & then some. I am very grateful to have been given this opportunity.

Do you feel you gained valuable skills? 

Absolutely. I got a chance to learn first-hand what it is like to see an experiment take shape from an idea or question. It was very enlightening to be involved in the literature review and experimental design process, execute the experiment, learn the data analysis portion, & see the end results of all the work.

What's next?

Tammy is currently working to publish her results and is on track to graduate with her B.S in December 2015.

Do you have any plans post-graduation?

Yes, after I take my board exam, I would like to acquire a position as a medical laboratory scientist, ideally in a hospital laboratory. I want to use my education in science to help people on a daily basis. After getting a few years of experience in the work force I would like to go to graduate school to pursue my PhD, & hopefully pass on these kinds of high quality internship experiences to other science students.

I want to extend a special thank you to the Tracy Farmer Institute, the Environmental Chemistry and Toxicology & Rhizosphere Science Laboratories at the University of Kentucky & to my mentor Rick Lewis. It means so much to me that they invested in my growth as an aspiring scientist.



© 2013 Tracy Farmer Institute for Sustainability and the Environment